432 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1945 



valescent sera. Therefore, in the prevention or treatment of any dis- 

 ease where the value of convalescent serum has been demonstrated, the 

 effectiveness of a concentrate from pooled normal plasma should be 

 investigated. If convalescent serum, or hyperimmune serum is frac- 

 tionated, still higher antibody titers may be obtained in the concen- 

 trated y-globulins, and their possible value in special cases must also 

 be considered. 



The concentrated antibodies, separated from the pooled plasma of 

 a population, offer a means of characterizing the state of immunity of 

 that population as a permanent public health record. Were such rec- 

 ords systematically collected and available, it might prove possible to 

 follow the course of epidemics much as the course of a comet may be 

 followed by the photographic records of the skies recorded by modern 

 observatories. Not infrequently the first faint trail of a comet has 

 escaped detection and the origin and course have been understood only 

 because astronomers now map all of the heavens systematically at all 

 times. The systematic collection and preservation as dry white 

 powders of the concentrated antibodies of diverse populations might 

 comparably simplify the analysis of the course of certain epidemics. 



Table 6. — Average concentration of various antibodies in solutions of normal 

 human serum y-globulins (Fraction II) 



Concentration 

 Antibody » referred to 



plasma 



Typhoid agglutinin, H 19 



Mumps, complement fixation 20 



Influenza A, complement fixation 18 



Influenza A, Hirst test 10 



Influenza A, mouse protection 23 



Diphtheria antitoxin 25 



Streptococcus antitoxin 22 



7-Globulin by electrophoresis 25 



• Titrations of Enders. 



Not all of the antibodies concentrated from human plasma will be 

 of value in the control of disease. However, in the case of measles, 

 where most susceptibles that are exposed are likely to contract the 

 disease, the concentrated antibodies have been employed with great 

 success, either to assure complete protection or by the use of a smaller 

 dose to modify the severity of the disease thus providing a lasting im- 

 munity with slight risk of those complications which make measles a 

 serious illness. The record of the use of the y-globulin antibodies in the 

 prophylaxis of measles is given in table 7. 



In the case of many diseases those bearers of immunity which are the 

 antibodies of the blood stream cannot be made available in amounts 

 large enough, or injected soon enough to prevent the onset of the dis- 



